Capsule filling machine for filling two-piece capsules, and method for filling two-piece capsules

Abstract

The disclosure relates to a capsule filling machine for filling two-piece capsules that each include a capsule upper part and a capsule lower part. The capsule filling machine includes a measuring device, the measuring device including a capacitive measuring system. The measuring device is downstream of the closing station. The capacitive measuring system includes a measuring section, along which the mass of the filled, closed capsule can be measured via the capacitive measuring system. The measuring device includes a guide device for the closed capsule, the guide device being configured to convey the filled, closed capsule from the capsule segment to the measuring section of the capacitive measuring system.

Claims

1. A capsule filling machine for filling two-piece capsules, the two-piece capsules each having a capsule upper part and a capsule lower part, the capsule filling machine comprising: at least one capsule segment having a plurality of receivers and being configured to convey the capsules, wherein said at least one capsule segment has a segment lower part configured to receive the capsule lower part and a segment upper part configured to receive the capsule upper part; an insertion station for delivering unfilled capsules into said plurality of receivers of said at least one capsule segment; a dosing station for filling the capsule lower part with a fill product; a closing station for closing the filled capsule lower part and the capsule upper part; a measuring device having a capacitive measuring system, said measuring device being downstream of said closing station, said capacitive measuring system having a measuring section, along which a mass of the filled, closed capsule can be measured via said capacitive measuring system; said capacitive measuring system including a capacitive sensor arranged at said measuring section; said measuring device including a guide for the closed capsule; said guide being configured to convey the filled, closed capsule from said capsule segment to said measuring section of said capacitive measuring system; and, a plurality of processing tracks, wherein said capacitive measuring system includes a separate one of said measuring sections for each of said plurality of processing tracks.

2. The capsule filling machine of claim 1 further comprising a further capacitive measuring system configured to measure a mass of unfilled capsules.

3. The capsule filling machine of claim 2, wherein said further capacitive measuring system is upstream of said insertion station.

4. The capsule filling machine of claim 1, wherein said guide has a lifting unit configured to lift the filled capsule out of said capsule segment and to position the filled capsule in said measuring section of said capacitive measuring system.

5. The capsule filling machine of claim 4, wherein said measuring device is arranged between said closing station and an ejection station.

6. The capsule filling machine of claim 1, wherein said guide has a guideway leading into said measuring section of said capacitive measuring system.

7. The capsule filling machine of claim 6, wherein said measuring section is inclined with respect to a direction of gravity (G).

8. The capsule filling machine of claim 6, wherein said measuring device is arranged downstream of an ejection station.

9. A method for filling two-piece capsules, each of the two-piece capsules having a capsule upper part and a capsule lower part, via a capsule filling machine, the capsule filling machine having a plurality of processing tracks, a capacitive measuring system including a separate measuring section for each of the plurality of processing tracks, and the capacitive measuring system having a capacitive sensor arranged at the measuring section, the method comprising: delivering, at an insertion station of the capsule filling machine, an unfilled capsule to a capsule receiver of at least one capsule segment; separating the capsule upper part and the capsule lower part from each other; filling the capsule lower part with fill product in a dosing station; closing the filled capsule lower part and the capsule upper part in a closing station; conveying the filled capsule via a guide to a measuring section of the capacitive measuring system; and, measuring a mass of the filled capsule in the measuring section via the capacitive measuring system.

10. The method of claim 9, wherein a mass of the unfilled capsule is measured via a further capacitive measuring system.

11. The method of claim 10 further comprising determining a mass of the fill product from a difference of the measured mass of the filled capsule and a measured mass of the unfilled capsule via a control system of the capsule filling machine.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0021] The invention will now be described with reference to the drawings wherein:

[0022] FIG. 1 shows a plan view of a capsule filling machine in a configuration according to the disclosure including a measuring device;

[0023] FIG. 2 shows a schematic lateral representation of the measuring device, the guide device and a capsule segment; and,

[0024] FIG. 3 shows a schematic lateral representation of an alternative embodiment of the guide device.

DETAILED DESCRIPTION OF THE INVENTION

[0025] FIG. 1 shows a plan view of an embodiment of a capsule filling machine 1 according to the invention for filling capsules 40 with a fill product 43 (see also FIGS. 2 and 3). The fill product 43 may be provided in the form of a powder, a granulate, tablets, liquids or the like. It may be a pharmaceutical preparation, a food supplement or the like. The capsules 40 are composed of a capsule lower part 41 and, attached thereto, a capsule upper part 42, both of which are made, for example, of hard gelatine.

[0026] The capsule filling machine 1 according to FIG. 1 comprises a rotary table 2 and a schematically represented main drive unit 4, with the rotary table 2 being drivable, by means of the main drive unit 4, to rotate about a vertical axis of rotation 3, in accordance with the direction of rotation 9, in indexed steps. The main drive unit 4 comprises at least one electric motor, which is operatively connected to the rotary table 2 and drives it. Preferably, the capsule filling machine 1 comprises a control system 30, which is coupled to the main drive unit. The control system 30 is also only represented schematically in dashed lines in FIG. 1. A number of capsule segments 5 are arranged at uniform angular intervals on a circumferential region of the rotary table 2. In the embodiment shown, a total of twelve capsule segments 5 are provided. A different number of capsule segments 5 may also be expedient. Each capsule segment 5 is composed of a segment lower part 6, which is preferably fixedly fastened to the circumferential region of the rotary table 2, and a segment upper part 7 that can be swiveled relative thereto. A plurality of fixed processing stations 11 to 22, which do not rotate with the rotary table 2, are positioned around the rotary table 2, and are not represented in detail in FIG. 1. The number of processing stations 11 to 22 preferably corresponds to the number of capsule segments 5, such that in each rotary position of the rotary table 2 indexed in angular increments, each capsule segment 5 comes to rest in the access region of respectively one of the processing stations 11 to 22.

[0027] In the preferred embodiment, the capsule segments 5 contain a plurality capsule receivers 8 for receiving the capsules. In the preferred embodiment, each capsule segment 5 contains five capsule receivers 8. It may be expedient to also provide a plurality capsule receivers 8, in particular ten, preferably twelve capsule receivers 8. In the preferred embodiment, the capsule receivers 5 are arranged in a linear, rectilinear row. If there is a large number of capsule receivers 5, they may also be arranged in two or more such rows.

[0028] The preferred embodiment of the capsule filling machine 1 comprises an insertion station 11, in which initially provisionally assembled empty capsules, composed of a capsule lower part 41 and a capsule upper part 42, are inserted. In normal operation, the attached capsule upper part 42 is separated from the capsule lower part 41. The next processing station is a reject station 12. Defective, unseparated empty capsules are rejected in the reject station 12. The next processing station is a discard station 12. Defective, unseparated empty capsules are discarded in the discard station 12.

[0029] After the discard station 12, the segment upper part 7 with the capsule upper parts 42 held therein is swiveled relative to the segment lower part 6 with the capsule lower parts 41 held therein. The segment lower part 6 is guided to the dosing stations 13, 14, 15, three in total in this case, that follow the discard station 12. In the dosing stations 13, 14, 15 the capsule lower parts held in the segment lower parts 6 are filled with the intended fill product 43. It may also be sufficient to provide only one or two dosing stations.

[0030] Following the passage through the last dosing station 15, the segment upper part 7 is swiveled, via the stations 16, 17, 18, back into the aligned position relative to the segment lower part 6. In the closing station 18, the capsules 40 are preferably closed in that the previously removed, or separated, capsule upper parts 42 are pushed back onto the filled capsule lower parts 41. Preferably, the capsule halves 41, 42 are locked together. The closing station 18 is followed by a plurality of checking stations 19, 20. In the checking stations 19, 20, capsules 40 are checked and if necessary rejected. In a subsequent ejection station 21, the remaining capsules 8 that are found to be good are ejected by means of pushers, or other ejection means not represented. The capsules 8 may also still be checked in the ejection station 21.

[0031] As shown in FIG. 1, the capsule filling machine 1 comprises a measuring device 22. The measuring device 22 is only represented schematically in dashed lines in the form of a square. The measuring device 22 serves to measure the mass of a capsule 40. The measuring device 22 is located downstream of the closing station 18. As indicated in FIG. 1, the measuring device 22 may be arranged, in terms of the process, between the closing station 18 and up to beyond the ejection station 21. Accordingly, only closed capsules 40 are measured in the measuring device 22. Of course, it may also be expedient to provide a plurality of measuring devices 22 in a capsule filling machine 1. It is to be noted at this point that the terms “upstream” and “downstream” are to be understood in terms of the process in relation to the processing of the capsules 40. Thus, if a first device is upstream of the second device, the capsules 40 in the capsule filling machine 1 first pass through the first device and then through the second device.

[0032] As shown in FIGS. 2 and 3, the measuring device 22 comprises a capacitive measuring system 23 and a guide/guide device 26. The capacitive measuring system 23 comprises at least one measuring section 25. Further, the capacitive measuring system 23 comprises a capacitive sensor 24 arranged at the measuring section 25. The capacitive sensor 24 generates an electric field that extends at least partially over the measuring section 25. When a capsule 40 is guided into the measuring section 25, it causes a change in the electric field, as a result of which the mass of the capsule 40 is calculated. As shown in FIG. 2, in a particularly preferred embodiment of the capsule filling machine 1, the capacitive measuring system 23 comprises a reference measuring section 25′ to determine the dielectricity of the environment. Thus, an even more accurate determination of the mass of the capsule 40 can be effected in the measuring section.

[0033] The guide device 26 of the measuring device 22 is configured to convey the capsule 40 from the capsule segment 5 to the measuring section 25 of the capacitive measuring system 23. FIG. 2 shows an embodiment of the measuring device 22, in which the guide device 26 comprises a lifting unit 27. The lifting unit 27 comprises a lower slider 32 assigned to the segment lower part 6, and an upper slider 33 assigned to the segment upper part 7. After the capsule upper part 42 and capsule lower part 41 have been closed, the entire filled capsule 40 is lifted out of the capsule segment 5 by the lower slider 32 and into the measuring section 25 of the capacitive measuring system 23. The measuring section 25 is realized as a measuring channel 34, the measuring channel 34 having a channel opening 35 at its end that faces towards the capsule segment 5. The capsule 40 can be pushed into the measuring channel 34 via the channel opening 35. Where the capsule 40 is transferred by the lifting unit 27, the measuring channel 34 and the capsule receiver 8 are approximately coaxial with each other. In a preferred execution, the lifting unit 27 may also be part of the closing station 18.

[0034] Once the capsule 40 is positioned in the measuring section 25, it is preferably fixed by the lower slider 32 and/or the upper slider 33. The mass of the closed and filled capsule 40 is measured in the measuring channel 34 by means of the capacitive measuring system 23. Following completion of the measuring process, the capsule 40 is placed back into the capsule receiver 8 of the capsule segment 5 by means of the lifting unit 27. Since not only the fill product 43 is measured when it is filled into the capsule 40, but the entire capsule 40 with fill product 43 in a closed state, the capacitive measuring process is non-dependent on the fill product 43 to be filled. Accordingly, liquid fill product or the like can also be measured. The capsule 40 can then pass through the further processing stations.

[0035] In an alternative configuration of the capsule filling machine 1, the lifting unit 27 may also have other means, instead of the sliders 32, 33, for lifting the capsule 40 out of the capsule segment 5 and/or for holding the capsule 40 in the measuring section 25. Such means may also be, for example, compressed air, vacuum or other mechanical elements.

[0036] An alternative configuration of the measuring equipment 22 is shown in FIG. 3. The guide device 26 likewise comprises a lifting unit 27. The lifting unit preferably comprises a pusher for lifting the capsule 40 on the capsule segment 5. It may also be expedient to provide another means for lifting the capsule 40. Further, the guide device 26 comprises a swivel arm having a capsule holder 38. In addition, the guide device 26 comprises a guideway 28, a portion of the guideway 28 preferably being realized as a measuring section 25. The capsule 40 is lifted out of the capsule segment 5 by means of the lifting unit 27 and pushed into the capsule holder 38 of the swivel arm 36. When the capsule 40 is in the capsule holder 38, it is held in the capsule holder 38 by holding means, not represented in more detail. Such a holding means could be, for example, a vacuum applied to the capsule holder 38. The swivel arm 36 then swivels, in a swivel direction 37, towards the guideway 28. When the capsule holder 38 is aligned approximately coaxially with the guideway 26, the capsule 40 is released and slides onto the guideway 26 due to gravity. In the present case, the guideway 26 is realized as a guide channel. It may also be expedient, however, for the guideway 26 to be of an open configuration, for example in the form of a trough. The capsule 40 slides down the guideway 26 and passes through the measuring section 25. The capacitive sensor 24 of the capacitive measuring system 23, which generates the electric field, is arranged at the measuring section 25. The capsule 40 passes through the electric field of the capacitive measuring system 23. The mass of the filled capsule 40 is measured. Measuring is effected as the capsule 40 slides through the measuring section 25, hence the measurement is dynamic.

[0037] As shown in FIG. 3, the guideway 28 is inclined with respect to the direction of gravity G. With the direction of gravity G, the guideway 28, in particular its longitudinal axis, encloses an angle α, the angle α being in a range of from 5° to 50°, in particular from 25° to 45°. The angle α is preferably about 40°. Compared to a drop shaft, this results in two substantial advantages that provide increased measuring accuracy. Firstly, the speed at which the capsule 40 passes through the measuring section 25 is reduced, and is approximately constant. Secondly, the capsule 40 is in permanent contact with the guideway 28 and thus has a fixed path of movement. Thus, the capsule 40 passes through the measuring section 25 approximately always at the same speed and the same position. As already mentioned at the beginning, this increases the measuring accuracy. The embodiment of the measuring device 22 with a guide device 26 according to FIG. 3 is preferably provided after the ejection station 21. Thus, the guide device 26 may even be part of the ejection device 26.

[0038] The capsule filling machine 1 comprises a plurality of processing tracks 44 along which a plurality of capsules 40 can be filled. As already explained above, in the present embodiment of the capsule filling machine 1 according to FIG. 1, five capsule receivers 8, and thus also five processing paths 44, are provided. For each processing lane 44, a measuring section 25 of the capacitive measuring system 22 is preferably provided, such that a lane-based measurement of the mass of the capsules 40 can also be effected. If it is determined that the mass of the fill product 43 differs from the target mass on a processing track 44, the individual stations can be checked for correctness along this processing track 44 without the need to check all stations of other processing tracks 44. In the case of the measuring device 22 according to FIG. 3, it may also be expedient, provided it is arranged after the ejection station 21 or is at least part of the ejection station 21, to provide only one measuring section 25. The capsules 40 are preferably guided sequentially onto the guideway 28, with the sequence of the capsules 40 of the various processing paths 44 being sensed by the control system 30. The measurement values of the capacitive measuring system 23 can thus be assigned to each capsule 40 of the corresponding processing path 44.

[0039] To determine the net mass of the filled capsule 40, that is, the mass of the fill product 43, the tare mass of the capsule 40 must be subtracted from the measured gross mass of the capsule 40. The tare mass of the capsules 40 is known and stored in the control system 30. However, the known tare mass of the empty capsules is merely a statistical mean value, which is either itself determined over a particular number of capsules 40 or is specified by the manufacturer of the empty capsules. Accordingly, there may be differences between the real mass of an empty capsule and the statistical mean value of the mass of the empty capsule. These differences can have a considerable effect on the total mass of a filled capsule 40, in particular in the filling of very small quantities of fill product 43. In a particularly preferred embodiment, therefore, the capsule filling machine 1 comprises a further capacitive measuring system 31, which serves to measure the mass of the empty capsules 40. The further capacitive measuring system 31 is an integral component of the capsule filling machine 1. The further capacitive measuring system 31 is preferably arranged before the insertion station 11 of the capsule filling machine 1, as schematically indicated by a dashed rectangle in FIG. 1. Alternatively, the further capacitive measuring system 31 may also be part of the insertion station 31. Technically, the further capacitive measuring system 31 is similar in structure to the capacitive measuring system 23. Even before the empty capsule 40 is separated into a capsule lower part 6 and a capsule upper part 7, it is guided into the measuring section, where its mass is measured. The measurement result is stored in the control system 30. After the same capsule 40 has been filled and its gross mass measured, the net mass is determined by the control system 30. For this purpose, the previously measured tare mass of the capsule 40 is subtracted from the gross mass. The measurement result is therefore extremely accurate, enabling the masses of even very small quantities of fill product to be determined with very high precision.

[0040] It is understood that the foregoing description is that of the preferred embodiments of the invention and that various changes and modifications may be made thereto without departing from the spirit and scope of the invention as defined in the appended claims.